Can I transmit 2 subaudible tones at once on a TK-272G ?

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n9gik
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Can I transmit 2 subaudible tones at once on a TK-272G ?

Post by n9gik »

Here's the situation. Our local 911 dispatches all fire and EMS from 151.385. Our VFD uses 154.205 as our talkaround and on scene freq. The next county uses 154.205 for dispatch and on scene both, so we haeve our HT's set up with decode on the subaudible tone so we only hear our own radios. (yes, they made a mistake in strategic planning, ':oops:' but I can't fix their mistakes.) We use 100.0 tone, they use 156.7.

In a mutual aid situation it would be helpful if we could transmit both our tone and theirs at the same time. As is I can be on scene talking to my guys and their guys can't hear me or vice versa.

I can set a channel with no decode so it hears everyone, but it still only transmits one subaudible tone. I'd like to set it up to trip both tones at once.

2 Questions.

1. Can a radio transmit 2 subaudibles tones at the same time?

2. Assuming yes, Is this possible on TK-272G's or TK-270's ?

OK, 3 questions. If if is possible how do I do it?
I don't know much about 2-way radios but I'm over 50 and can't remember not having one around. Everything from Buddy and Citi-fone to Icom and Kenwood.
Libuff
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Post by Libuff »

from my basic background in physics, it would be simply impossible to transmit mutliple CTCSS (PL) tones at once... if you were to transmit two tones together, it would sound like DTMF. which is Dual Tone Multi Frequency.

better yet... im curious if u transmitted DTMF with two PL tones if it would work... im curious...

anyway... i've never seen any radio to have dual PL transmit or receive... but i can be wrong...
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Meatball
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Post by Meatball »

There's no way to make the radio send two subaudible tones.

Maybe you could convince the other department to program in a channel with carrier squelch receive. That's about the only way to accomplish it.
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ohgary
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Post by ohgary »

One would wonder HOW APCO cordinated the same freq for two agencies so close.
k2hz
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Post by k2hz »

Meatball wrote:There's no way to make the radio send two subaudible tones.

Maybe you could convince the other department to program in a channel with carrier squelch receive. That's about the only way to accomplish it.
If everybody on the mutual aid scene switches their units to CSQ receive there should be no problem communicating.
DES-AJ
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Post by DES-AJ »

I don't know how we got from a Kenwood Analog portable to Digital radio but hey its all good... Is the 272/270 capable of OST? (Operator Selectable Tones) If it can be programmed both radio fleets should be programmed with an OST "CSQ/PL Disable/Tone Off/etc..." setting and than for situations where comms are needed to be used between both areas you switch all the radios to a No tone setup... Otherwise you could just setup another channel with out the CTCSS to save on PF button use plus it would make it easier to use for all the bunnies that will be using the radios etc.

Either way all radios will needed to be reprogrammed...

HTH

AJ
jim202
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Post by jim202 »

This sounds like typical mutual aid with no planning. Haven't
you boys ever heard of "INTEROPERABILITY" before. Most
regional agencies sit down and work up a MOU (memorandum
of understanding) on just how they will work the radio comms
on mutual aid calls.

In most cases, some radio channel is set aside for the mutual
aid comms. Even the FCC managed to allocate a number of
channels for "National Interoperability". These are on most
of the common bands. You have them at VHF, UHF and 800 MHz.
There are a number of them at 700 MHz, but the designation
of them is rather unclear.

You and your surounding agencies would be much better off to
work up the use of these mutual aid channels and then use
them when ever you all get together in a typical cluster. Just
remember that it takes a strong incident command to keep
things working smooth. Some one needs to be the focal point
and be the command at the scene.

Jim
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ohgary
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Post by ohgary »

You can always program one of your channels to your home freq but with the gues PL. You waste a channel but it will work.
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Meatball
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Post by Meatball »

Gentlement, press your monitor buttons!
Birken Vogt
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Post by Birken Vogt »

For what it's worth:

A radio CAN be made to transmit 2 or 3 or 10 different PL tones if that's what you need. Most commonly done with repeaters for obvious reasons. With modern repeaters it's all done with software programming. Older repeaters you just installed one PL encode board per tone required to be transmitted.

The radio you are talking about will only transmit one tone ON ITS OWN, in software. If you put another tone from a standalone board into the low level modulator input, you can have it transmitting another tone at the same time. It will involve custom modification and the addition of another PL board though. The radio will not "know" it is transmitting another PL tone and it won't be changeable through software or anything.

Birken
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n9gik
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Post by n9gik »

Meatball wrote:Gentlement, press your monitor buttons!
As programmed from the factory the monitor button disables the squelch only while holding it in. But I got to to studying the programming software and as I understand it I can program a button to toggle the tone squelch off and on. So, I programmed the lower side button to do that. We'll have to try it in the field and see if it does whta I understand it to do.
I don't know much about 2-way radios but I'm over 50 and can't remember not having one around. Everything from Buddy and Citi-fone to Icom and Kenwood.
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